Mapping Quatitative trait loci involved with resistance against Russian Wheat Aphid (Diuraphis noxia) in a population of Double haploid recombinant lines.

RICCIARDI M., CASTRO A.M., TOCHO E., TACALITI M.S., BARRAGAN M., GIMÉNEZ D., VASICEK A., BARRENECHEA M., SIMMONDS J. AND SNAPE J.

PLANT BREEDING

Blackwell

Lugar: Berlin, Alemania; Año: 2008

0179-9541

Diuraphis noxia (RWA), the most aggressive pest of wheat, has evolved several biotypes virulent to the Dn resistance genes. The fast deployment of resistance requires the assessment of new sources. This paper was aimed at determining the location of plant-defence genes triggered by RWA in a set of recombinant doubled haploid (RDH) lines obtained from the cross between UK wheat varieties Spark and Rialto. Both parental lines and 110 RDH were screened for antixenosis and tolerance mechanisms of resistance with a population of RWA collected in Argentina. Antixenosis was significantly linked to marker locus gwm33 located on 1AS and to gwm193 on 6BS. Tolerance traits showed significant associations with several chromosomes. The foliar area developed during infestation was significantly associated with marker loci gwm11 (1BS), wPt9857 (1DS), psp3103 (4DS), and gdm3 (5DS). The chlorophyll content in the infested plants was significantly linked to marker loci gwm533 on 3BS, and to psp3094 on 7AL and the number of expanded leaves was associated with marker loci wmc264 (3AS) and to wPt-8836 (4DS). Most of the tolerance traits were significantly associated with the same chromosome interval on chromosomes 4DS and 5DS. The 4DS QTLs are linked to, or are a pleiotropic effect of, Rht-D1. These new genes can be designated as new QDn.unlp genes, following the rules for gene nomenclature in wheat. Several novel genes conferring antixenosis and tolerance to RWA have been identified and these could be included in wheat cultivars to enlarge the genetic base of defence against this aphid pest.